If you’re an electrical engineer or a student learning AutoCAD Electrical, you’ve probably come across the DOL (Direct-On-Line) Starter circuit. It’s one of the simplest and most widely used motor starting methods, especially for small to medium-sized induction motors. In this blog, I’ll walk you through how to create a DOL Starter Power Diagram in AutoCAD Electrical, step by step.
What is a DOL Starter?
A Direct-On-Line (DOL) Starter is a basic motor starter circuit used to start a three-phase induction motor. It consists of:
✅ MCCB (Molded Case Circuit Breaker) – Protects against short circuits
✅ Contactor – Acts as a switch to control motor power
✅ Overload Relay – Protects against overheating and overload conditions
✅ Push Buttons (Start/Stop) – Controls the motor operation
When you press the start button, the contactor energizes, connecting the motor directly to the power supply. When you press stop, the circuit opens, disconnecting the motor.
Steps to Create a DOL Starter Power Diagram in AutoCAD Electrical
Step 1: Open AutoCAD Electrical and Set Up a New Project
1️⃣ Launch AutoCAD Electrical and create a new project.
2️⃣ Set up the drawing sheet with the correct dimensions and title block.
3️⃣ Select the appropriate schematic template for your diagram.
Step 2: Insert Electrical Components
Now, add the main components for the DOL Starter Power Circuit:
✔ MCCB – Drag and place it as the main power protection device.
✔ Contactor – Insert it in series with the motor connection.
✔ Overload Relay – Place it after the contactor for motor protection.
✔ Motor – Add a three-phase motor symbol at the output.
Step 3: Draw Power Connections
🔹 Use the wiring tool in AutoCAD Electrical to connect:
-
MCCB to Contactor
-
Contactor to Overload Relay
-
Overload Relay to Motor
💡 Tip: Use line numbering and color coding for clear identification.
Step 4: Add Control Wiring
-
Insert a Start Button (NO) and Stop Button (NC)
-
Connect the start button to the coil of the contactor
-
Connect the stop button in series with the coil
-
Add a holding contact from the contactor to maintain the latch
This setup ensures that when the start button is pressed, the motor starts and stays ON. When the stop button is pressed, the circuit opens, turning the motor OFF.
Final Touch – Label and Save the Diagram
✔ Use the text tool to label each component clearly.
✔ Number your wires and components for easy troubleshooting.
✔ Save the diagram in DWG format for future use.
🎯 And that’s it! You’ve successfully created a DOL Starter Power Diagram in AutoCAD Electrical!
Why is This Important?
✅ Essential for industrial motor control
✅ Helps in troubleshooting and maintenance
✅ Widely used in factories, HVAC systems, and pump stations
If you're learning AutoCAD Electrical or working on electrical projects, mastering the DOL Starter is a great skill to have.
💡 Want more tutorials like this? Subscribe to Easy Electra on YouTube for step-by-step videos on electrical design, PLC programming, and industrial automation! 🚀
👉 Follow for more AutoCAD Electrical tips! 🔥
Post a Comment